文献类型：期刊文献

英文题名：Thermodynamic modeling of CO2 hydrate formation in electrolyte solutions based on a modified cubic-plus-association equation of state

作者：Zhou, Ying[1];Liu, Bowen[2];Shi, Jialin[2];Wang, Bohong[3];Lu, Hongfang[1]

机构：[1]Chinese Acad Sci, Ningbo Inst Mat Technol & Engn, State Key Lab Adv Marine Mat, Ningbo 315201, Peoples R China;[2]East China Univ Sci & Technol, Sch Chem & Mol Engn, Shanghai 200237, Peoples R China;[3]Zhejiang Ocean Univ, Natl & Local Joint Engn Res Ctr Harbor Oil & Gas, Zhejiang Key Lab Pollut Control Port Petrochem Ind, Zhoushan 316022, Peoples R China

年份：2026

卷号：361

外文期刊名：ENERGY

收录：;EI(收录号：20263121199149);Scopus(收录号：2-s2.0-105045825452);WOS:【SCI-EXPANDED(收录号:WOS:001837999600001)】；

语种：英文

外文关键词：Carbon capture; Utilization and storage (CCUS); Thermodynamic modeling; Phase equilibria; CO2 hydrate; CO2 solubility; Cubic-plus-association equation of state (CPA EOS)

摘要：In carbon capture, utilization, and storage (CCUS), CO2 hydrates may enable deep-sea storage but can also be unintentionally formed during offshore CO2 water-alternating-gas (CO2-WAG) operations, potentially blocking subsea pipelines. Therefore, accurate prediction of hydrate stability in electrolyte solutions is critical for storage design and reliable operation. However, many existing thermodynamic models do not accurately reproduce key physical properties such as liquid density and CO2 solubility, which can lead to noticeable deviations in predicted phase boundaries at high salinities. To address these limitations, this paper presents a Cubic-Plus-Association (CPA) equation of state (EOS)-based thermodynamic model with a constant volume translation for predicting phase boundaries of CO2 hydrates in brines. The modified CPA EOS accounts for hydrogen bonding in the waterrich phase and captures specific CO2-H2O interactions, thereby improving liquid density predictions. We simulate three-phase (hydrate-liquid water-vapor) equilibria by coupling the modified CPA EOS with the Chen-Guo model, Pitzer-Mayorga-Zavitsas-Hydration (PMZH) model, and Sun et al.'s CO2-brine solubility model. The model is validated against experimental data over wide ranges of temperature, pressure, and salinity. The mean absolute percentage errors (MAPEs) in equilibrium pressure are 2.81% for single-electrolyte solutions and 4.28% for mixed-electrolyte solutions. Overall, this framework provides a practical basis for hydrate-risk screening and operating-window design in offshore CO2 transport and storage in saline environments.